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NASA Rover Set to Land on Mars

August 05, 2012 8:13 AM

Suzanne Presto

The area where NASA's Curiosity rover will land on Aug. 5 PDT (Aug. 6 EDT) has a geological diversity that scientists are eager to investigate, as seen in this false-color map based on data from NASA's Mars Odyssey orbiter.

The nuclear powered, one-ton rover, called Curiosity, will hunt for evidence of microbes on Mars and harvest a host of data and images from the planet. But first it has to land safely, completing an eight-month journey.

NASA scientists say the landing of the Curiosity, which is traveling at a speed of 21,240 kilometers per hour, is the most challenging they have ever attempted.

If the landing is successful, Curiosity will begin unlocking clues about possible life on Mars.

The rover is the size of a car, and has 17 cameras, a robotic arm, a laser and a drill.

If Curiosity carried business cards, they might read: "Curiosity, geochemist, U.S. space agency."

NASA video about Curiosity

Roving Geochemist

Curiosity is the first rover that has the ability to sample rocks and soil on Mars and analyze them using instruments within the rover.

Mars Exploration Program lead scientist Michael Meyer praised the sophisticated new rover at a NASA news briefing.

"It is a laboratory," Meyer stressed. "It's amazing that we can do chemistry and we can do mineralogy there on the surface, and, in many ways, any geologist would die to have something like this with them when they're out in the field."

The Curiosity rover is the centerpiece of the $2.5 billion Mars Science Laboratory mission. It launched aboard an Atlas V rocket last November. Since then, it has traveled some 560 million kilometers toward its destination, the Red Planet.

The nuclear-powered Curiosity will investigate Martian geology, weather and radiation levels during its two-year mission on Mars. The main goal is to see if the area ever had environmental conditions that could have supported microbial life, but it's not a life detection mission.

Landing site

A team of space agency scientists selected the landing site -- the foot of a mountain within a deep, 150-kilometer-wide depression called Gale Crater. The peak is informally known as Mount Sharp.

Project Scientist John Grotzinger says the mountain's layers provide a record of the way Mars evolved.

"This Mount Sharp that sticks up gives us this time dimension that has never been explored before," he explained.

Radiation spikes

The Mars Science Lab is already yielding data. Its Radiation Assessment Detector has been collecting information during the journey to Mars. That's helpful as NASA develops plans to send astronauts to Mars one day.

Don Hassler, the principal investigator for the radiation detector, says scientists noted radiation spikes. He said they were not at lethal levels, but they would factor into the radiation dose limit that NASA has established for astronauts.

"It's a significant fraction," Hassler told reporters. "We're still analyzing those and reducing those data to get the exact numbers, but it's a significant contribution to an astronaut's career limit."

"7 minutes of terror"

Before Curiosity touches down on the Martian surface, it faces a harrowing entry and descent.

The craft will be functioning autonomously. In fact, NASA engineers will not even be able to witness the events in real time because it takes 14 minutes for radio signals to reach Earth from Mars.

Curiosity will be traveling at about 20,000 kilometers per hour when it hits the thin Martian atmosphere. It will have only seven minutes to reduce its speed to about three kilometers per hour to make a soft landing on the dusty surface of Mars.

First, it has to steer itself to stay on course for the landing site. Then, a parachute will deploy to slow its descent. There's no back-up parachute if something goes wrong. After the rover separates from the parachute, its rocket backpack fires up for a powered descent. Then a skycrane will lower Curiosity on cables to the Martian surface before cutting loose.

Engineers had to develop this new system for Curiosity because it is too heavy to use the airbag system that worked for smaller rovers.

NASA engineers refer to this entry, descent and landing period as "seven minutes of terror."

Excitement, anxiety

Adam Steltzner of NASA's Jet Propulsion Laboratory says three of those seven minutes will be particularly grueling.

"Certainly the novelty of the guided entry and especially the novelty of the skycrane maneuver at the end draw a lot of the attention of the team's anxiety. There's also that parachute that we use. It ends up that parachutes are fundamentally sketchy kinds of devices, right?"

If successful, Curiosity will be the seventh NASA spacecraft to land on the Red Planet.